“It’s easy to forget what’s lurking in our world – things we don’t see everyday,” says McGill University biology professor Christopher Buddle by phone from Montreal. Then, before launching into what’s known so far about the saga of the Arctic pseudoscorpion, he adds: “Each of these species has its own fascinating biology and its own story to tell.”
Buddle’s recent paper, “Life History and Distribution of the Arctic pseudoscorpion, Wyochernes asiaticus (Chernetidae),” was published in the Canadian Field Naturalist earlier this month. And the story, picked up by mainstream media, grabbed the attention of folks who would never have guessed that two- to three-millimetre creatures armed with pincers were lurking under rocks beside streams in the Far North.
Grizzlies, caribou and silver foxes steal the natural history show on the Dempster. But as Buddle reminds us, “smaller wildlife is ecologically important and has a role to play … as much as moose and bears.” And we never know just when a little-known, small organism might add to our understanding of climate variations and ecological stresses.
Buddle came across a publication on the Arctic pseudoscorpion in 2008. They’d been found under rocks where Sheep Creek crosses the northern Dempster Highway in the Yukon. That fact stuck with him. When he and his students were studying spiders in the Yukon, they drove past a sign for Sheep Creek. “I slammed on the brakes and the whole team of us got out of the truck and wandered down to the riverside and started flipping rocks, and lo, we found these tiny pseudoscorpions well above the Arctic Circle.” Buddle was hooked and decided to pursue the Arctic resident and see just what surprising research paths it might reveal.
“There wasn’t a big research grant or a big question I had in mind,” he says. The study was about passion, about curiosity, and about intriguing life-puzzles. Every time he returned to the Yukon, he had the pseudoscorpion added to his territorial research permit.
Pseudo – or “false” – scorpions are, like “true” scorpions – those with a stinger in their tails – arachnids, but of different orders, as are spiders and daddy long legs,
Wyochernes asiaticus was first described in North America by scientist and author William B. Muchmore of Rochester, N.Y. Muchmore called it a new species: Wyochernes arcticus. But Buddle happened on a subsequent paper by William Muchmore which showed that W. arcticus was the same as W. asiaticus, a species found in Tibet, Siberia and other parts of eastern Asia.
Buddle wondered if W. arcticus was common across North America, or if it was mainly found in unglaciated regions of the northwest. “While searching for the pseudoscorpions, it became very clear that though we were able to find it on the Dempster, it certainly wasn’t found further south in regions that were glaciated during the last (glacial) maximum,” he says.
“In North America the species is limited to the northwest, although its global distribution includes parts of Asia,” Buddle wrote in his paper. “I report on some life history traits, based on examination of nearly 600 specimens from localities in the Yukon and Northwest Territories.” These specimens included pseudoscorpions at all stages of development, and 17 per cent of them were females toting brood sacs of eggs.
Our new pincered pal is apparently a relic of Pleistocene Beringia. Buddle doesn’t know how long the organism has been in North America. It would take an in-depth molecular study to reveal just how long it’s been here and how it got here.
The same goes for trying to determine what this particular pseudoscorpion feeds on and what feeds on it. Buddle knows the pseudoscorpions are predators, but has never seen them actually dining.
He suspects the pseudoscorpion itself has few predators. It is hard-shelled and very small and probably more work than it is nutritionally worth for most other animals to pursue.
“What we do know about the pseudoscorpion is that the only way they can travel long distances is by a process known as phoresy: they hitchhike on animals, perhaps beetles and other insects, and perhaps small vertebrates,” he says. “Whatever they ride does a pretty good job of getting them up these rivers.”
Why do the scorpions prefer the underside of rocks found only at the high-water mark of streams so that they’ll get covered by water during spring floods and left dry in summer? Why don’t they live further away, and in earth that could be – from our perspective at least – more stable? Other species of pseudoscorpions around the world live under bark, under birds’ nests, and in sea-wrack at intertidal zones, among other seemingly secure places.
“It’s sort of frustrating and exhilarating as a scientist to discover two things about something and at the end of the day find 10 more things all needing an answer,” says Buddle.
What does the professor tell his students to look for when stalking Arctic pseudoscorpions?
They are reddish brown, but matte, not shiny. They’re pear-shaped, have a hardened exoskeleton and two pincers – or chela – extending from branches on either side of their heads.
Spiders have toxins in their fangs. Scorpions have toxins in their tails. These pseudoscorpions pack toxin in their claws. “They will handle and grasp prey and inject venom through those pincers and they bring it to their mouths where they sort of macerate and suck up the contents of their prey,” says the scientist.
If a student were pinched by a pseudoscorpion, would it ruin her field day, as a sting from a true scorpion could? Apparently not. The pincers aren’t strong enough to pierce human flesh, nor are the toxins strong by our standards, says Buddle.
In his paper on Arctic pseudoscorpions, Buddle describes his subject as a “charming arachnid.” Charming is not a word one sees often, if ever, in academic scientific writing. Why does this researcher apply it to Arctic pseudoscorpions, of all things?
“It’s a curious unusual creature in an unusual part of the world,” says Buddle. “Charming just comes to mind. They have a lot of swagger to them and a bit of character to them – in much the same way as the male cardinal outside my window that wakes me up each morning with such vigour.”
Yes, that’s anthropomorphising a bit, he admits with a chuckle, then adds: “There’s something that makes them stand out among all the other species of the world, something a little extra.”
This column is co-ordinated by the Yukon Research Centre at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at www.yukoncollege.yk.ca/research/publications/your_yukon